Xyris ambigua, the coastal plain yelloweyed grass, is a North American species of flowering plant in the yellow-eyed-grass family. It is native to southern and eastern Mexico (Tamaulipas, Veracruz, Tabasco, Chiapas, the Yucatán), Central America (Belize, Honduras, Nicaragua), Cuba, and the southeastern and south-central United States (from Texas to Virginia inland to Tennessee and Arkansas). Xyris ambigua is a perennial herb up to 100 cm (40 inches) tall with grass-like leaves and yellow flowers.